Printer

Abstract

A printer includes a printing unit having a printing head and a platen positioned opposite the printing head, the printing head being configured to print on a print medium that is fed between the printing head and the platen, a ribbon holding shaft configured to hold an ink ribbon that is wound thereon, a ribbon winding shaft configured to wind and collect the ink ribbon supplied from the ribbon holding shaft, and first and second guide shafts provided along a feeding route of the ink ribbon between the ribbon holding shaft and the ribbon winding shaft to apply tension to the ink ribbon. At least one of the first and second guide shafts has a tilt adjuster that applies a twist to the ink ribbon in a width direction of the ink ribbon through said at least one of the first and second guide shafts.

What is claimed is: 
     
       1. A printer comprising:
 a printing head; 
 a platen positioned opposite the printing head; 
 a ribbon holding shaft configured to hold an ink ribbon that is wound thereon; 
 a ribbon winding shaft configured to wind and collect the ink ribbon supplied from the ribbon holding shaft via an ink ribbon feeding path that passes between the printing head and the platen; and 
 first and second guide shafts provided along the ink ribbon feeding path between the ribbon holding shaft and the ribbon winding shaft to apply tension to the ink ribbon, 
 wherein the ribbon holding shaft, the ribbon winding shaft, and the first and second guide shafts extend along a width direction of the ink ribbon, and at least one of the first and second guide shafts has a first end portion having a supporting pin extending along a ribbon feeding direction and a second end portion opposite to the first end portion, the second end portion being rotatable around the supporting pin to apply a twist to the ink ribbon in the width direction of the ink ribbon. 
 
     
     
       2. The printer according to  claim 1 , wherein the ribbon holding shaft and the ribbon winding shaft each have a fixed end on the same end as the first end portion and a free end on the same end as the second end portion. 
     
     
       3. The printer according to  claim 1 , wherein the first guide shaft is on the ribbon holding shaft side of the ink ribbon feeding path and the second guide shaft is on the ribbon winding shaft side of the ink ribbon feeding path, and the second guide shaft has the first end portion and the second end portion. 
     
     
       4. The printer according to  claim 3 , wherein the second end portion of the second guide shaft is movable by a cam mechanism including a cam that is in contact with the second end portion of the second guide shaft and is rotatable to displace the position of the second end portion of the second guide shaft, to apply the twist to the ink ribbon through the second guide shaft. 
     
     
       5. The printer according to  claim 4 , wherein the cam mechanism has a ratchet mechanism, and a rotation of the cam causes the position of the second end portion of the second guide shaft to displace in a stepwise manner through the ratchet mechanism. 
     
     
       6. The printer according to  claim 5 , wherein the cam has a knob that is rotatable by an operator to control an amount of the twist applied to the ink ribbon through the second guide shaft. 
     
     
       7. The printer according to  claim 1 , further comprising:
 a first spring member urging the second end portion in a first rotational direction around the pivotal shaft supporting pin. 
 
     
     
       8. The printer according to  claim 7 , further comprising:
 a second spring member urging the second end portion in a second rotational direction around the supporting pin, the second rotational direction being opposite to the first rotational direction. 
 
     
     
       9. The printer according to  claim 1 , wherein the supporting pin extends in the first end portion. 
     
     
       10. A method of correcting a twist of an ink ribbon in a printer that is fed from a ribbon holding shaft to a ribbon winding shaft via an ink ribbon feeding path that passes between a printing head of the printer and a platen of the printer, said method comprising:
 applying tension to the ink ribbon using a first guide shaft on the ribbon holding shaft side of the ink ribbon feeding path; 
 applying tension to the ink ribbon using a second guide shaft on the ribbon winding shaft side of the ink ribbon feeding path; and 
 pivoting the second guide shaft about a supporting pin extending along a ribbon feeding direction at a first end portion thereof to apply a twist to the ink ribbon in a width direction of the ink ribbon. 
 
     
     
       11. The method according to  claim 10 , further comprising:
 rotating a cam that is contact with a second end portion of the second guide shaft to pivot the second guide shaft about the supporting pin at the first end portion thereof. 
 
     
     
       12. The method according to  claim 11 , further comprising:
 controlling a rotational position of the cam in a stepwise manner using a ratchet mechanism.